Help with vintage frog

[Sandcrawler72 0]

Hi there. I have dug out my 30yr old Frog. When I plug in the power, the motor runs at full belt. Can anyone shed any light on what the fault could be. 
 

many thanks

 

[Saito2 6686]

Assuming the Frog still runs a mechanical speed controller (MSC), did you have the transmitter switched on before plugging in the battery and turning the car (receiver) on? If the car is turned on and the battery simply plugged in, the throttle servo attached to the mechanical speed controller can "jump" or simply be stuck with the MSC on full throttle. If you pull the throttle servo back to the neutral position, the motor should stop if there isn't a short somewhere.

[Biz73 603]

Did you look at the trim on your transmitter? I've had the old 2 stick Futaba Tx's get pushed all the way up or down while walking to my usual running spot.